Aperture Exporter should transfer GPS data from multiple sources including Aperture, camera metadata, or other applications. When Aperture recognizes location information, the exported image should contain it.
However, the developers have identified an unusual situation where this may not occur. It's either an Aperture bug, or a problem with the user default plist settings. None of this is the user's fault.
Recommended Fix
Navigate to Aperture preferences and access the Export tab. Verify that "Include location info" is selected. If already enabled, toggling this setting off and back on may resolve the problem.
If this troubleshooting step doesn't resolve the issue, try toggling the setting off and back on again, then restarting Aperture before retrying the export.